Visualizing Quaternions This mixed-level tutorial provided an intuitive connection between quaternion lore and many standard problems in representation, interpolation, and exploitation of orientation frames in graphics and visualization. It began with an attempt to construct an entirely pictorial intuition of what quaternions are and why we should use them to study orientation frames. A range of interactive images was exploited, including images representing individual quaternion rotations, the action of rotations in quaternion space, and the visual properties of quaternion splines and related animation optimization procedures. For those who think that applications of quaternions to graphics stop with animation, the tutorial continued with a wide variety of additional ways to exploit quaternion frames, ranging from creating optimal tubings and multidimensional VR navigation techniques, to oriented streamlines and local surface textures.   Organizer Andrew Hanson Indiana University   Lecturer Andrew Hanson Indiana University